线程休眠

模拟网络延时

放大问题的发生性

//模拟网络延时:放大问题的发生性
public class TestSleep implements Runnable{
    //票数
    private int ticketNums = 10;

    @Override
    public void run() {
        while (true){

            if(ticketNums<=0){
                break;
            }
            //模拟延时
            try {
                Thread.sleep(200); // 毫秒
            } catch (InterruptedException e) {
                e.printStackTrace();
            }

            System.out.println(Thread.currentThread().getName()+"拿到了第"+ticketNums--+"张票");
        }
    }
    public static void main(String[] args) {

        TestSleep ticket = new TestSleep();
        new Thread(ticket,"小明").start();
        new Thread(ticket,"小红").start();
        new Thread(ticket,"小华").start();


    }
}

模拟倒计时

//模拟倒计时
public class TestSleep2{

    public static void main(String[] args) {
        try {
            tenDown();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

    public static void tenDown() throws InterruptedException{
        int num = 10;
        while (true){
            Thread.sleep(1000);
            System.out.println(num--);
            if(num<0){
                break;
            }
        }
    }

}

打印系统当前时间

    public static void main(String[] args) {

       //打印当前系统时间
        Date date = new Date(System.currentTimeMillis()); //获取系统当前时间
        while (true){
            try {
                Thread.sleep(1000);
                String format = new SimpleDateFormat("HH-mm-ss").format(date);
                System.out.println(format);
                // 更新系统当前时间
                date = new Date(System.currentTimeMillis());

            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }